I think bringing in Sabretooth would be too complicated after Origins and X1. Do they make him related to Logan or not? But Origins technically happened and audiences might remember it or do they just push on through with whatever they want to do and rewrite Victor as they see fit? It would be cool but I think if we are going to explore familial relations I'd rather see it done with Quicksilver and Nightcrawler rather than do Victor again.

But I really liked Liev as Sabretooth. But I think Magneto's Brotherhood consisting of Toad, Quicksilver and someone like Cannonball would be cool. Blob might be kinda goofy, esp. against Apocalypse if we end up having the X-Men and Brotherhood against him, so Cannonball might be more visually appealing. I'd be alright with Ink too and Wanda if they wish.